Over the past several decades, a number of advancements in the art of roasting coffee beans, nuts, and the like have taken place. For example, the introduction of relatively small kitchen-sized coffee bean roasters was a significant development in the art, permitting the roasting process to be performed at home rather than in a store or restaurant. As another example, it is now recognized that faster and better roasting is made possible through "fluidizing" during the roasting process. In other words, better results are achieved when the food items being roasted are circulated via air flow within a vessel (i.e., when such items are "fluidized") while being roasted.
Roasting food matter by fluidizing the food is, of course, limited to food matter which is in the form of a plurality of relatively small items. For example, roasters which fluidize an amount of food during the roasting process are commonly used to roast coffee beans, nuts, and the like. Therefore, although the remainder of this disclosure makes reference only to roasting coffee beans in a coffee bean roaster, it should be noted that the present invention can be used for roasting any food item in the form of multiple parts capable of being fluidized.
An important feature of most coffee bean roasters utilizing a fluidized bean roasting method is the manner in which the beans flow or are circulated within the roasting vessel. Each fluidizing design attempts, with mixed success, to achieve uniform bean circulation while keeping as many beans as possible floating within the roasting vessel. Notwithstanding the existence of several roaster designs in which coffee beans are fluidized during roasting, however, a roaster capable of fully fluidizing a charge of coffee beans with minimal air flow force and roasting beans in a uniform manner remains a somewhat elusive goal.
Another problem with conventional coffee bean roasters regards the connection commonly existing between the coffee bean roasting vessel (in which the coffee beans are placed and are contained during the roasting process) and the connected apparatus emitting the hot air flow for roasting coffee beans within the vessel. Typically, this connection is preferably relatively fluid tight so as to ensure adequate internal pressure between the connected apparatus and the coffee bean roasting vessel. A fluid tight connection helps to prevent pressure loss through the connection and reduces the chance of coffee beans, hulls, debris, etc. from exiting the roaster between the roasting vessel and the connected apparatus. The connection is also preferably designed to prevent coffee beans, hulls, and/or debris from falling from the coffee bean roasting vessel into the connected apparatus for those roaster designs in which the vessel rests atop an air emitting base or housing.
Many prior art coffee bean roasters have a permanently secured roasting vessel within the roaster and therefore do not have sealing arrangements which permit user insertion and removal of the roasting vessel. In those conventional coffee bean roasters which do have a removable roasting vessel, a fluid-tight seal between the vessel and the base or housing is typically created via an annular seal or bead surrounding a bottom portion of the roasting vessel or by a compression and gasket mechanism. The annular seal or bead arrangement is subject to wear with repeated insertion and removal of the roasting vessel, and depends heavily upon a precise fit between the roasting vessel and the base or housing. Compression and gasket mechanisms commonly used for removable roasting vessels are relatively complex and therefore are expensive to manufacture. As such, conventional sealing arrangements are generally less than optimal.
Also, conventional connection designs often either do not adequately protect against beans, hulls, or debris from falling into the apparatus connected to the roasting vessel, do so at the expense of a connection which is either difficult and expensive to manufacture or is hard to clean, or do not protect against waste and dust escaped during roasting from re-entering the roaster. Despite the large number of roaster designs which attempt to establish a sufficient vessel-to-base/housing seal and to prevent matter from falling or being drawn via air intake into the base or housing connected to the roasting vessel, a simple, fully effective, reliable and easy to clean connection between the roasting vessel and the base or housing has not been introduced.
In light of the problems and limitations of the prior art described above, a need exists for a coffee bean roaster in which improved airflow ensures better coffee bean roasting results, which utilizes a reliable and easily cleaned and manufactured seal between the roasting vessel and its base or housing, and which protects components (such as a fan, heater, and motor) within the base or housing from debris falling or being drawn into the base or housing or being drawn into the base or housing via air intake. Each preferred embodiment of the present invention achieves one or more of these results.